Abstract

OBJECTIVES

Near-infrared spectroscopy of the collateral network (cnNIRS) has recently been trialled to monitor real-time tissue oxygenation of the paraspinous vasculature as a surrogate for spinal cord tissue oxygenation. This large animal study was designed to investigate the correlation between cnNIRS and spinal cord oxygenation by comparing it to laser Doppler flowmetry (LDF), a proven method for direct oxygenation and flow assessment.

METHODS

Measurements were performed in seven animals. Four paravertebral cnNIRS optodes were positioned bilaterally at thoracic and lumbar levels to assess tissue oxygenation of the paraspinous vasculature. Paravertebral muscle and spinal cord oxygenation and microcirculatory flow were measured directly using LDF probes. LDF and cnNIRS were compared during consecutive repeated periods of descending aortic cross-clamping for 8 min and recovery by clamp release.

These experiments confirm that the paraspinous vasculature in the presented large animal model is directly linked to spinal cord microcirculation and that the regional paraspinous muscle oxygenation status reflects spinal cord tissue oxygenation. As lumbar cnNIRS reproducibly depicts tissue oxygenation of the paraspinous vasculature, it can be used for non-invasive spinal cord oxygenation monitoring in real-time.